Be warned: for Joe and Jane Prospectiveinvestorsmith, it’ll be very difficult to scoop up a share of one’s very own. Brokerage houses like Charles Schwab and TDAmeritrade have activity and account-balance cutoffs for all interested parties.The Los Angeles Timeshas some practical, if blunt, advice: “If you’re a small investor seeking a piece of the Facebook initial public offering, here’s the bad news: You’re too late and you’re too poor.” Defriended!